scholarly journals Morphological assessment raises the possibility of cryptic species within the Luristan newt, Neurergus kaiseri (Amphibia: Salamandridae)

2019 ◽  
pp. 237-244
Author(s):  
Mansoureh Malekian
Keyword(s):  
Geometric Morphometrics ◽  
Morphological Variation ◽  
Conservation Planning ◽  
Body Shape ◽  
Genetic Data ◽  
Species Level ◽  
Inadequate Knowledge ◽  
Morphological Distinction ◽  
Conservation Of Biodiversity ◽  
Morphological Assessment

One of the main challenges in the conservation of biodiversity is to overcome inadequate knowledge about species and their intra-specific diversity. In the present study, we attempted to assess morphological distinction of the two previously identified genetic clades within the Luristan newt (Neurergus kaiseri, Schmidt 1952) endemic to Iran, which is essential for its conservation planning. Signals of the morphological variation in N. kaiseri were evaluated using landmark-based geometric morphometrics of body shape and characters of osteological structures. Morphological approaches revealed consistent groupings within the species, confirming the presence of two distinct lineages (previously named as the northern and southern clades). The morphological and genetic data provide evidence for the possible co-existence of two species in N. kaiseri and we recommend assigning the newly recognised forms to the species level.

How unique is unique? Quantifying geometric differences in stripe patterns of Cape mountain zebra, Equus zebra zebra (Perissodactyla: Equidae)

2020 ◽  
Author(s):  
Nicolas D Prinsloo ◽  
Martin Postma ◽  
P J Nico de Bruyn
Keyword(s):  
Geometric Morphometrics ◽  
Morphological Variation ◽  
Individual Animal ◽  
Shape Variation ◽  
Model Species ◽  
Degree Of Branching ◽  
Pattern Similarity ◽  
Surface Models ◽  
Coat Pattern ◽  
Study Population

Abstract Quantified coat pattern dissimilarity provides a visible surface for individual animal traceability to populations. We determined the feasibility in quantifying uniqueness of stripe patterns of Cape mountain zebra (CMZ; Equus zebra zebra) using geometric morphometrics. We photogrammetrically created dense surface models of CMZ (N = 56). Stripe edges were landmarked, superimposed and compared for shape variation across replicates and the population. Significant allometry in stripe patterns prompted allometric correction to remove increased curvature of stripes at the rump, belly and back with larger adult individuals, to facilitate equilibrated comparison between individuals. Re-landmarked replicates showed lower dissimilarity (Di) than non-replicates (Dp), representing minimal landmarking error. Individuals were 78.07 ± 1.79% unique (U=1−DiDp×100%) relative to the study population. Size, the number of torso stripes and degree of branching in four rear torso stripes described the most shape variation (36.79%) but a significant portion could only be distinguished with geometric morphometrics (41.82%). This is the first known use of geometric morphometrics to quantify coat pattern uniqueness, using a model species to provide baseline individual morphological variation. Measures of coat pattern similarity have a place in phenotypic monitoring and identification.

scholarly journals Morphometric Variation as an Indicator of Genetic Interactions Between Black-Capped and Carolina Chickadees at a Contact Zone in the Appalachian Mountains

The Auk ◽  
2000 ◽  
Vol 117 (2) ◽  
pp. 427-444 ◽  
Author(s):  
Gene D. Sattler ◽  
Michael J. Braun
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Markers ◽  
Hybrid Zone ◽  
Morphological Variation ◽  
Genetic Data ◽  
Mixed Ancestry ◽  
Morphometric Variation ◽  
Average Gene ◽  
Hybridization And Introgression

AbstractWe studied hybridization and introgression between Black-capped (Poecile atricapillus) and Carolina (P. carolinensis) chickadees along two transects in the Appalachians using four genetic markers and multivariate analysis of morphology. Genetic data revealed that at least 58% of the birds in the center of each transect were of mixed ancestry and that recombinant genotypes predominated among hybrids, demonstrating that hybridization is frequent and that many hybrids are fertile. Genetic clines generally were steep and coincident in position, but introgression was evident well beyond the range interface. Introgression was higher at the one autosomal locus surveyed than in mitochondrial DNA or in two sex-linked markers, suggesting that the hybrid zone is a conduit for gene flow between the two forms at some loci. On a broad scale, morphometric variation was concordant with genetic variation. Clines in morphological variation based on principal components (PC) scores were steep and coincident with genetic clines. Also, a strong correlation within a population between PC scores and an individual's genetic makeup suggested that a large amount of morphological variation was genetically determined. However, morphological analysis indicated that hybrids were uncommon on one transect, whereas genetic data clearly showed that they were common on both. In addition, patterns of morphological variation were equivocal regarding introgression across the hybrid zone. Thus, genetic data provided a complementary and more detailed assessment of hybridization, largely due to the discrete nature of genetic variation. Genetic markers are useful in understanding hybridization and introgression, but diagnostic markers may underestimate average gene flow if selection against hybrids maintains steep clines at diagnostic loci. To gain a clearer picture of the genome-wide effects of hybridization, a much larger number of loci must be assayed, including non-diagnostic ones.

Larval morphology in four species of Hylarana from Vietnam and Thailand with comments on the taxonomy of H. nigrovittata sensu latu (Anura: Ranidae)

Zootaxa ◽  
2009 ◽  
Vol 2051 (1) ◽  
pp. 1-25 ◽  
Author(s):  
ANNA GAWOR ◽  
RALF HENDRIX ◽  
MIGUEL VENCES ◽  
WOLFGANG BÖHME ◽  
THOMAS ZIEGLER
Keyword(s):  
National Park ◽  
Body Shape ◽  
Developmental Stages ◽  
Molecular Data ◽  
Species Level ◽  
Larval Morphology ◽  
Chiang Mai ◽  
Central Vietnam ◽  
Wide Gap ◽  
Morphological Differences

We describe the tadpole morphology of four species of Hylarana based on larval specimens identified by DNA barcoding. Of these, the larvae of Hylarana attigua and H. maosonensis, two species recently recorded from Phong Nha – Ke Bang National Park, Quang Binh Province, central Vietnam, had not been previously described; in addition, descriptions of the tadpoles of syntopic H. guentheri and H. nigrovitatta are provided as well. The tadpoles of these four species are generalized exotrophic lentic-benthic forms of Orton’s Type 4 with a depressed body shape, dorsolaterally positioned eyes and a moderate height of tail fins. In contrast to the silver-whitish H. guentheri the preserved tadpoles of H. attigua, H. maosonensis and H. nigrovittata are greenish-brown to greyish. The generalized oral discs exhibit a wide gap of marginal papillae on the upper labium and elongated papillae on the lower labium. In general, the keratodont row formulae of the Hylarana species studied herein is 2(2)/3(1) (sometimes 1/3(1) in H. guentheri). Differences between species mainly concern body shape, size in different developmental stages as well as number and shape of oral papillae. H. nigrovittata larvae from near Chiang Mai in northern Thailand mainly differ from Vietnamese specimens in the number and shape of oral papillae. In concert with adult morphological differences and molecular divergences by molecular data this indicates species-level distinctness of the Vietnamese versus the northern Thai populations.

Larvae and pupae of Dascillidae (Coleoptera): morphological study and discussion of their relationships to Scarabaeoidea and Eulichadidae

2003 ◽  
Vol 34 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Clarke Scholtz ◽  
Vasily Grebennikov
Keyword(s):  
North America ◽  
Morphological Variation ◽  
Morphological Study ◽  
Body Shape ◽  
Sister Group ◽  
Close Relative ◽  
Sister Group Relationship ◽  
Larval Morphology ◽  
The Family ◽  
Late Instar

AbstractExternal morphology of late-instar larvae and pupae of the coleopteran family Dascillidae is revised. Larvae studied for Dascillus Latreille with two species from Europe and North America, Notodascillus Carter from Australia and Pleolobus Philippi from Chile; pupae studied for D. davidsoni LeConte. Larval diagnosis and description of the family are updated. Dascillid larvae exhibit little morphological variation and share eight apparently apomorphic characters. Widely accepted sister-group relationship between Dascillidae and Rhipiceridae is not supported with larval morphology because ectoparasitic larvae of Rhipiceridae are poorly known and apparently highly modified morphologically. The superfamily Scarabaeoidea is unlikely to be a close relative of Dascillidae since this hypothesis is based mainly on habitat-dependent convergences of soil-dwellers (grub-like body shape, reduced stemmata) or possible symplesiomorphic similarities. Ten similarities between larvae of Dascillidae and Eulichadidae (Dryopoidea) were found. Some of these are possibly synapomorphies of these two groups. Larval and pupal morphology of Dascillidae is illustrated by 26 drawings.

scholarly journals The Utility of Geometric Morphometrics to Elucidate Pathways of Cichlid Fish Evolution

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Michaela Kerschbaumer ◽  
Christian Sturmbauer
Keyword(s):  
Geometric Morphometrics ◽  
Evolutionary Biology ◽  
Body Shape ◽  
Cichlid Fish ◽  
Anatomical Landmarks ◽  
Trophic Specialization ◽  
Geometric Morphometric ◽  
The Family ◽  
Morphometric Methods ◽  
Head Morphology

Fishes of the family Cichlidae are famous for their spectacular species flocks and therefore constitute a model system for the study of the pathways of adaptive radiation. Their radiation is connected to trophic specialization, manifested in dentition, head morphology, and body shape. Geometric morphometric methods have been established as efficient tools to quantify such differences in overall body shape or in particular morphological structures and meanwhile found wide application in evolutionary biology. As a common feature, these approaches define and analyze coordinates of anatomical landmarks, rather than traditional counts or measurements. Geometric morphometric methods have several merits compared to traditional morphometrics, particularly for the distinction and analysis of closely related entities. Cichlid evolutionary research benefits from the efficiency of data acquisition, the manifold opportunities of analyses, and the potential to visualize shape changes of those landmark-based methods. This paper briefly introduces to the concepts and methods of geometric morphometrics and presents a selection of publications where those techniques have been successfully applied to various aspects of cichlid fish diversification.

Molecules match morphology: mitochondrial DNA supports Bayer's Lytreia - Bebryce - Heterogorgia (Alcyonacea : Octocorallia) clade hypothesis

2010 ◽  
Vol 24 (1) ◽  
pp. 23 ◽  
Author(s):  
Sergio Vargas ◽  
Michael Eitel ◽  
Odalisca Breedy ◽  
Bernd Schierwater
Keyword(s):  
Mitochondrial Dna ◽  
Molecular Phylogeny ◽  
Phylogenetic Relationship ◽  
Morphological Variation ◽  
Mitochondrial Marker ◽  
Morphological Studies ◽  
Close Phylogenetic Relationship ◽  
Morphological Assessment ◽  
Molecular Characters

Several studies attempting to clarify the taxonomy and systematics of Octocorallia have highlighted the important role of molecular characters in corroborating or rejecting previous hypotheses based on morphological variation. One such hypothesis is that of a close phylogenetic relationship between the genera Lytreia, Bebryce and Heterogorgia proposed by Bayer based on morphological studies of the genera. Herein, we tested Bayer’s hypothesis using the mitochondrial marker mshI. We deduced a molecular phylogeny including members of the families Gorgoniidae and ‘Paramuriceidae’ that corroborated the existence of Bayer’s Lytreia–Bebryce–Heterogorgia clade. In addition, we provide a morphological assessment of the three genera as well as diagnoses for each of them. We also discuss, based on the phylogenetic results obtained, the evolution of sclerite morphology within Bayer’s Lytreia–Bebyce–Heterogorgia clade. Finally, we propose a Tethyan origin for the Lytreia–Bebryce–Heterogorgia clade.

scholarly journals Sources of Intraspecific Morphological Variation in Vipera seoanei: Allometry, Sex, and Colour Phenotype

2020 ◽  
Author(s):  
Nahla Lucchini ◽  
Antigoni Kaliontzopoulou ◽  
Guillermo Aguado Val ◽  
Fernando Martínez-Freiría
Keyword(s):  
Geometric Morphometrics ◽  
Morphological Variation ◽  
Morphological Variability ◽  
Tail Length ◽  
Shape Variation ◽  
Body Proportions ◽  
Head Shape ◽  
Relative Contribution ◽  
Colour Morphs ◽  
Intraspecific Morphological Variation

AbstractSnakes frequently exhibit ontogenetic and sexual variation in head dimensions, as well as the occurrence of distinct colour morphotypes which might be fitness-related. In this study, we used linear biometry and geometric morphometrics to investigate intraspecific morphological variation related to allometry and sexual dimorphism in Vipera seoanei, a species that exhibits five colour morphotypes, potentially subjected to distinct ecological pressures. We measured body size (SVL), tail length and head dimensions in 391 specimens, and examined variation in biometric traits with respect to allometry, sex and colour morph. In addition, we analysed head shape variation by recording the position of 29 landmarks in 123 specimens and establishing a low-error protocol for implementing geometric morphometrics to European vipers. All head dimensions exhibited significant allometry, while sexual differences occurred for SVL, relative tail length and snout height. After considering size effects, we found significant differences in body proportions between the sexes and across colour morphs, which suggests an important influence of lowland and montane habitats in shaping morphological variation. By contrast, head shape did not exhibit significant variation across sexes or colour morphs. Instead it was mainly associated to allometric variation, where the supraocular and the rear regions of the head were the areas that varied the most throughout growth and across individuals. Overall, this study provides a thorough description of morphological variability in Vipera seoanei and highlights the relevance of combining different tools (i.e. linear and geometric morphometrics) and analyses to evaluate the relative contribution of different factors in shaping intraspecific variation.

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